This invention relates to 6-aryl-pyridine thiosemicarbazones which are useful as insecticides, compositions containing those compounds, methods of using said compounds and compositions.
The search for compounds which have a combination of excellent insecticidal activity and low undesirable toxicity is a continuing one because of factors such as the desire for compounds exhibiting greater activity, better selectivity, low undesirable environment impact and effectiveness against insects resistant to many known insecticides.
Compounds of the present invention are particularly suitable for controlling plant-destructive insects in crops of cultivated plants, ornamentals and forestry.
Certain pyridine thiosemicarbazone derivatives have been disclosed in the literature.
In U.S. Pat. Nos. 4,317,776 and 4,493,930 certain 2-acetyl- and 2-propionylpyridine thiosemicarbazones which are substituted on the 4-nitrogen atom are disclosed. These compounds are useful as bactericides and antimalaria agents.
In J. Agric. Food Chem., 1983, 31, 713-718, and Pesticide Biochem. and Physiol., 1982, 17, 35-41, certain 2-acetylpyridine thiosemicarbazones are disclosed as inhibitors of ecdysis.
In J. of Pharm. Sci., 1984, 73, 1763-1767, certain 2-acetylpyridine thiosemicarbazones are disclosed as antimalarial and antibacterial agents.
In J. Med. Chem., 1984, 27, 87-91, certain 2-acetylpyridine thiosemicarbazones are disclosed as potential antimalarial agents.
In J. Med. Chem., 1979, 22, 855-862, certain 2-acetylpyridine thiosemicarbazones are disclosed as antimalarial agents.
In European Patent Application No. 153340-A, thiosemicarbazones of methyl 2-pyridyl ketones are disclosed as biocides.
In Pest. Sci., 1984, 25, 462-470, certain thiosemicarbazones of methyl 2-pyridyl ketones are disclosed as having ecdysis inhibiting activity.
In J. of Med. Chem., 1974, 17, 631-635, certain 2-formyl(m-amino)phenylpyridine thiosemicarbazones are disclosed as antineoplastic agents.
In U.S. Pat. No. 4,405,791, certain arylthioureido pyridinecarbamino compounds are disclosed as plant growth regulators.
In Bull. Inst. Chem. Chin. Acad. Sci., 1978, 25, 113-131, certain thiosemicarbazones of 4-bromophenyl- and 2-chlorophenylpyridine-2-carboxaldehydes are disclosed as having antineoplastic activity.
The 6-aryl-pyridine thiosemicarbazones of the present invention differ from known compounds primarily by their 6-position substituent on the pyridine ring.
Compounds of the present invention are also distinguished by their insecticidal activity and selectivity against lepidopteran larvae without material adverse impact on beneficial insects.
It is believed the compounds of the present invention exhibit anti-juvenile hormone activity. When the compounds of the present invention are consumed by larvae, said larvae undergo a premature lethal metamorphosis. This activity is believed to be unique to this class of compounds.